If you know something about patisserie, you have probably seen the use of nut pastes--hazelnut and pistachio seem to be the two most popular that I see. And for good reason because they taste fantastic and they're versatile. You can introduce them into a dessert as is or use them as a flavor in buttercream, mousse, pastry cream or in some other creative way.
Though, there are a couple of problems with them. For one thing, I notice that they are difficult to find in brick and mortar stores (they're certainly easy enough to find online). But, the second issue is that they are expensive. The good news is that they are easy to make on your own. All you need is a food processor or blender and a candy thermometer.
Ingredients:
125g raw, shelled pistachios (not roasted or salted)
30g almond flour
60g granulated sugar
20 grams of water
1/8tsp of almond extract
1-2T (approximately, divided) flavorless oil such as grapeseed or vegetable
Directions:
First toast the pistachios in the oven. Set the oven temperature to 300F. Place the pistachios on a rimmed baking sheet in one layer. Toast them in the oven for 12-15 minutes. Make sure they brown a bit but don't burn. They'll start to smell quite fragrant. Once done, remove them from the oven and set aside.
Next, place the sugar and water in a medium saucepan and bring to a boil over medium-high heat. Once it starts to boil use a candy thermometer and cook until it reaches 250F. Once it reaches that temperature, remove it from the heat, pour the toasted pistachios into the saucepan and stir them into the sugar syrup using a wooden spoon or heat-resistant spatula. The goal here is to ensconce all of the nuts with the sugar syrup. The syrup will start to crystallize and that is normal and ok. After the crystallization has occurred, pour the pistachios into the bowl of a food processor (or blender but I prefer the food processor).
Add to the food processor bowl the rest of the ingredients but just 1 tablespoon of the oil and begin processing the mixture. It will go through stages where it becomes powdery, then clumpy and finally it will start to smooth itself out. At this point you need to determine how viscous you want your paste. If it seems too thick, add another 1/2 tablespoon of oil and then run the processor once more. Stop and check the processor again to check the viscosity. Add another 1/2 tablespoon of oil if you want it to be thinner and run the processor again until smooth.
Once you have achieved the consistency you want, you can store the pistachio paste in a jar or other container for later use. I usually store mine in the refrigerator and it keeps for quite a while.
Note:
The amount of oil you need seems to vary--in my experience. From what I've read, sometimes you really don't need a lot because once you start processing the nuts, the heat generated from the machine will sort of draw the natural oils out of the pistachios and force them into cohesion. But, that's never happened for me. So, I usually end up adding enough additional oil until I get the consistency I desire. Perhaps it's the type of nuts I use or my processor isn't powerful enough--not sure. Either way, I'm always pleased with the product.
